"Most beads would likely be produced in Venice, Italy or are of a Czech or Dutch origin."

Just one of the excavated beads was made of limestone, says Wesley, and this would have originated in Southeast Asia itself.

Based on how the objects were made, he says it is possible to tell where the glass beads came from.

Wesley says the beads are about 2 millimetres in diameter and include those that can be threaded to make necklaces or beaded fabrics.

While beads have been found in archaeological sites before and are known to have been used by Aboriginal people for decoration, they were always argued to have come from European missionaries after 1916.

But Litster and Wesley used radiocarbon dating of sediments and found some dated back to the 18th Century.

"Ethnographic, historical, and archaeological research now provides irrefutable evidence for beads in Indigenous society in both the pre-Mission and the early Mission era."

Macassan link

Wesley says the age of the beads coincides with the time that Macassan seafarers were fishing off Arnhem Land, long before Europeans made it to the area.

He says according to many Aboriginal customs, one cannot cross another person's traditional lands without asking permission and acknowledging their ownership in some way.

Building on the earlier work of archaeologist Professor Campbell MacKnight, Wesley and Litster argue that the beads were used by Macassans in negotiating access to Aboriginal lands. Interestingly, the Aboriginal words for beads are also Macassarese words, says Wesley.

Macassans came from what is now known as the Indonesian island of Sulawesi, to harvest trepang (also known as sea cucumber or bêche-de-mer) off Arnhem Land.

The trepang were boiled and dried on land and then taken back to Indonesia before being sold on to China as a delicacy.

"This was Australia's first export resource industry," says Wesley. "The middle men were the Macassans."

The beads were excavated from trepang processing sites and rock shelters in Arnhem Land.

Wesley says Indonesia was "flooded with beads" from Europe after the 17th Century which is why the Macassans would have come in contact with them and brought them to Arnhem Land.

Other glass beads found at the Wellington Rages could have been brought by Europeans who arrived in the area after 1840, and used along with flour and tobacco to gain access to country for buffalo shooting, lumber getting and pastoral industries.

Active negotiation

Wesley says Aboriginal people benefited by developing this "market economy" with the Macassans, for example by getting access to new technologies such as dugout canoes.

He says the beads are an indication that Aboriginal people were not passive partners in a one-way relationship.

"The Arnhem Land indigenous society created this relationship with outsiders so that they traded, and bartered and worked with them. They had this two-way interaction," says Wesley.

He says the findings could have implications for native title claims, which are based on the idea that Aboriginal people actively negotiated with Macassans, prior to contact with Europeans, to give access to their traditional fishing areas.

At last, says Wesley, hard archaeological evidence supports what has to date only been "sketchy" and mostly anthropological evidence that such negotiations took place.